Abstract: In order to achieve synchronous discharge of dual-chambers of an ArF excimer laser based on master oscillation power amplifier(MOPA) structure, synchronization logic was used to respond to dual-chamber discharge timing sequence quickly. According to synchronization control logic, an automatic precision adjustment to dual-chamber delay was made. Coarse search was implemented by using a high-speed synchronous modulo-16 binary counter and dual-chamber delay difference was narrowed quickly. Small precision delay adjustment was achieved by using universal digital programmable delay chip. The results show that discharge time differences steadies at about 23ns less than ±3ns synchronization jitter after dual-chamber discharge synchronous adjustment. It can meet MOPA structure excimer laser synchronous control requirements under high repetition frequency of 4kHz.